1. Field of the Invention
The present invention relates to a data repeating apparatus in which local area networks (LANs) are connected through a communication network so that a frame is relayed between the LANs.
2. Description of the Related Art
Conventionally, in relaying a frame-form network layer data to other networks through lines of a communication network, a call should be established between the networks for the data relay. This requires use of telephone number data.
In a conventional repeating apparatus, sets of destination address data for network layer data and telephone number data are prepared corresponding to the number of network layer addresses which require relay or repetition. First, the repeating apparatus retrieves a corresponding telephone number in accordance with destination addresses of the network layer data to be relayed. Then, the apparatus establishes a call in accordance with the retrieved telephone number, and connects with the other side of the network layer address through lines of a communication network, thereby effecting data relay with the remote side.
In this repeating apparatus, the telephone numbers must be set in a table therein in a manner such that they correspond to all the network layer addresses which require data communication. If connection with the network layer addresses is actually prevented by a change of network topology or the like, moreover, the repeating apparatus inevitably undergoes operation for unnecessary line connection with the remote side. In order to prevent this unnecessary line connection, in the repeating apparatus, the telephone numbers must be set manually.